Because of things like this:
Republican senator who has questioned whether an abortion opponent could win approval to the U.S. Supreme Court must agree to back President Bush’s nominees if he is to head the committee acting on those nominations, the Senate’s Republican leader said.
Bush has four years to fill Supreme Court seats with basically no opposition. He doesn’t have to think about future re-election anymore. He has a majority in both houses and a huge debt to the far-right conservative Christian groups. Stacking the court to overturn Roe v. Wade may be only the beginning.